HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR DETERMINATION OF THE METABOLISM OF POLYUNSATURATED MOLECULAR-SPECIES OF PHOSPHATIDYLSERINE LABELED IN THE POLAR GROUP

A reversed-phase HPLC method to monitor the incorporation of radiolabe led precursors into the polar group of individual polyunsaturated mole cular species of phosphatidylserine (PS) is presented. PS labeled in t he polar group was decarboxylated and subsequently converted to trinit rophenyl-phosphatidylethanolamine (Tnp-PE), which was separated into i ts molecular species by reversed-phase HPLC within 90 min, using a gra dient of acetonitrile-methanol and ammonium acetate. A major feature o f the method is the complete resolution of the stearoyl species, 18:0/ 20:4 and 18:0/22:6, at ambient temperature. By determining the amount of radioactivity incorporated into each fraction, the metabolism of in dividual molecular species of PS, and also of PE, labeled in the polar group can be investigated.